Up to this time, there has been no commercially available silicon nitride fibers or whiskers which are essentially all beta silicon nitride whiskers. Since the beta silicon nitride phase is the high temperature stable phase for silicon nitride, it is the desired phase for use in ceramics, ceramic composites or as fibrous material for use as a thermal barrier coating or tile. A technique described by NASA's Jet Propulsion Laboratory, Pasadena, Calif. produces beta silicon nitride whiskers about 1 micrometer in diameter and up to about 5 centimeters long over a cork like mass of submicron beta sialon whiskers. The disadvantages of this method are that (1) sialon whiskers are the major phase present and are not as stable as pure beta silicon nitride whiskers at high temperatures, (2) whiskers are formed on the inside of a tube made of firebrick only 1" in diameter which suggests that it may be only a laboratory process, (3) a silica/carbon coating is painted on the inside of a tube of firebrick and, therefore, it would be difficult to control the final reactant concentrations, and (4) upscale of this process has not been demonstrated.